Preheater for furnaces



C. D. BIDWELL.

PREHEATER FOR FURNACES.

APPLICATION FILED SEPT. 13, 1918.

Patented June zs, 1921 3 SHEETS-SHEET I.

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C. D-. BIDWELL- PREHEATER FOR FURNACES.

APPLICATION FILED SEPT. 13. 1918.

Patented June 28, 1921.

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- C. D. BIDWELL.

PREHEATER FOR FURNACES. APPLICATION FILED SEPT. 13, I918.

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UNITED STATES TENT OFF-ice.

CARLYLE n. nrnwnnn, or MILWAUKEE, WISCONSIN, ASSIGNOR, BY Mrsrm ASS-IGN-mmrs, r0 INTERNATIONAL nmvns'rnacomram, A. conroaa'rron or- NEW JERSEY.

PREHEA'IER FOR FURNACES.

. Specification of Letters Ilatent. Patented J 11116 28, 1921Application filed September 13, 1918. Serial Fe. 253,973.

To all 'wlz-oin it may concern:

Be it known that I, CARLYLE D.'Bn)w.eLL a citizen of the United States,residing at Milwaukee, in the county of Milwaukee and State ofWisconsin, haveinvented certain new and useful Improvements inPreheaters for Furnaces, of which the following is a full, clear, andexact specification.

This invention relates to furnaces and especially to oil burningfurnaces. An object of the invention is to increase the efliciency ofsuch furnaces by means of a more perfect combustion of the fuel.

Heretofore it has been very diflicult to obtain a uniform and completeburning of the fuel where oil was used under the varying heat conditionsrequired of the average forge shop furnace. Incomplete combustion offuel in an oil burning furnace results in a smear of oil around thefurnace, a coating within the furnace of oil anda collection of carbonon the, furnace walls, and often the production of. clouds of dense,foul smoke from the furnace, which renders the air unfit to breathe andmakes ventilation very difficult.

Another object is to provide means for recovering some of the heat ofthe waste gases and return some of this heatyto the furnace, at the sametime affording a protection to the workman and rendering the cooledwaste gases easier to handle and lessening the labor required toventilate the furnace room.

With. these and other objects in view, my invention consists in thecombination and arrangement of parts herein described and covered in theappendedelaims. Reference is now had to the drawings in which,-

Figure 1 is a front elevation of a furnace showm the pre-heating coilsin, place and the coo in coils and metal of'the'cooling front part ybroken away;

Fig. 2 is an end elevation of the furnace; Fig. 3 is a plan view of thefurnace; Figci 4 is a section on the line 4.--4 of Fig. 1 an Fig. 5 is asection on the line 55 of Fig. 4. r v The furnace 10. which I havechosen to illustrate in connection with my invention, consists of thefront wall 11 having a single opening 12 on a level with the floor 13 ofthe furance, and the end walls 14, the back wall single embodiment ofmy-invention, it is to 15, the top 16, and bottom 17.

The furnace has the usual features of the oil burning furnace having anozzle at each end. Alr 1s supplied through a pipe 19 and by branches 2Qto the headers 21. As shown 'in Fig. 4 each header has a partition22dividing the header into inlet. and outlet chambers 21 and 21". Theseare connected by a series ofputgoing pipes 23, return bends 24 andreturn pipes 25. These pipes are arranged in the headers in multiple sothat the air can leave thechamber 21 through any one of the pipes'23 andreturn to the chamber 21 through the corresponding pipe 25.

.These pipes 23 and 25 are placed in the path of the hot furnace gasesso that the gases must pass around the pipes asthe gases leave theopening 12. After the hot air has made thecircuit of the pipes 23 and 25to the chamber 21, it then passes through the pipe 26 and the valve 27to the nozzle 28.

' nace and below theopening 12. This pipe is supplied with air from themain air supply pipe 19. The eflect of these jets is to substantially Icause the hot waste gases to pass up between 5 the front of the furnaceand the protecting front. This consists of' a steel plate 34 backed-witha series of pipe coils-35. Water is forced through these coilsand outthrough the overflow pipe 35' where it is caught in the basin" 36 andled to a drain. Thewater pipes and metal front are carried on supports37 and the space surrounding the pipes .is filled with a material 38 oflow heat conductivity, such as asbestos.

The operator is thus protected by the front which are caused to flow upbehind the pro- .tecting front,=as well as from injury due to directcontact with the water cooled front.

While I have shown and'described but a berunder'stlood that it iscapable of many modifications. Changes, therefore, in the form andarrangement may be made without departing fromthe spirit and scope ofthe invention as disclosed in the appended claims.

What I claim as my invention and desire to secure by Letters Patent is:

1. In a.furnace having a nozzle at the end and a charging door at theside, the combi nation of a water-cooled shield in front of saiddoor, apassage between said sh1e1d and said furnace, means for causing thewaste sageway for waste gases, one of the walls of said passageway beingcooled means in said ases to pass up between the shield and the urnace,and means for extracting heat from the waste gases in said passagewayand for returning'the heat to the nozzle. v

2. In a furnace, the combination of a pastubes connecting said chambers,and oil heating means in oneof said chambers.

4. A water cooled front for furnaces, comprising a sheet metal screenand water coils arranged behind said screen, and means for 'passin waterthrough said coils and mate- I rial 0 7 low heat conductivitysurrounding said water coils. r

5. In 'a furnace having a charging door,

the combination of a shield infront of. said door and spaced from thefurnace to pro vide-a passage for the waste gases, means for extractingheat from the waste gases, said means comprising a header having aplurality of chambers at one-side of the waste gas passage, and meansconnecting the chambers.

andextending into the passage.

6. In a furnace having a charging door,

.the combination of a shield in front of said door and s aced from thefurnace to provide a passage or the waste gases, means for extractingheat from the waste gases, said means comprising a header havin aplurality of chambers at one side of tiew'aste gas passage, meansconnecting the chambers and extending into the passage, and means tocirculate a fluid through said' chambers and connecting means.

7 In a furnace having a charging door. the combinationof a shield infront of sai 'door and spaced from the furnace to provide a passage forthe waste gases, means for extracting heat from the waste gases, saidmeans comprising a header having a plurality of chambers atone side ofthe waste gas passage, means connecting the chambers and extending intothe-passage, and fuel heating means in one of said chambers.

,8. In a furnace having a charging dooi the combination of a shield infront of said door and spaced from the furnace to provide a passage forthe'waste gases, means for causing the waste'gases to pass-upwardbetween the shield and furnace, means for extracting heat from the wastep gases, said means comprising a header having a plurality ,of chambersat one side of the Waste gas passage, and means connecting the chambersand extending into the passage.

9. A preheater forfurnaces having a fuel nozzle comprising, a headerhaving a plurality of chambers, means for supplying a fluid to be heatedto one of said chambers, a fuel heating coil in a second chamber,c0nduits connecting said chambers and adapted to be heated by the wastegases from the furnace whereby the fluid supplied to the first chamberwill be heated and will in turn heat the fuel coil in the secondchamber, and

. means for conducting the heated fluid and fuel to the fuel nozzle ofthe furnace.

10. In a furnace having a charging door,

thecombination of a shield spaced from said door to provide a passagefor the waste gases, means for causing'the waste gases to passupward-through the passage, means for coolin the rear side of saidshield, a header at eac side-of the shield, means for supplying a fluidto'the headers to be heated,

conduits connected to "the headers and extending into the passage forwaste gases whereby the fluid will be heated, fuel heating means in oneof said headers a fuel nozzle for said furnace, and means for conductingthe heated fluid and fuel to said fuel nozzle. v

11. In a furnace having a charging door,

the combination of a shield in front of the K door and spaced from thefurnace to provide a passage for waste gases, a source of air supplyunder pressure, a r-heating means in said passageway, means fordirecting aflow of air upward through said passageway and meansconnecting said source of air supply to the air heating means and to themeans for directing-a flow of air.

12. In a furnace having an open charging door, the combination of ashield in front'of said door spaced from the furnace to provide apassage for waste'ga ses, means for cooling the shield, air heatingmeansfor said passage, means for directing a flow of air througconnecting said source of air supply with the air heating. means and thedirecting means.

In testimon whereof I afiix m si nature. ARLYLE D BI LL.

said passage and separate means

